β-淀粉样蛋白对BV2小胶质细胞促炎作用的研究

目的探讨β-淀粉样蛋白(β-amyloid,Aβ)促进BV2小胶质细胞产生炎性因子IL-1β和TNFα的作用机制。方法体外培养BV2小胶质细胞,应用Aβ1-42作用于BV2小胶质细胞,或用吡咯烷二硫代氨基甲酸盐(PDTC)预孵育再给予Aβ1-42刺激,实时荧光定量反转录聚合酶链反应法(RT–PCR)检测IL-1β和TNFαmRNA表达;免疫印迹法(Western blot)检测胞核中NF-κB p65及其抑制蛋白胞浆中IkBα的表达。结果 Aβ1-42作用于BV2小胶质细胞后,Westernblot显示胞浆内IkBα表达下降,胞核内NF-κB p65表达明显增加,RT-PCR测定IL-1β和TNFαmRNA的表达增加;给予NF-κB信号通路特异阻断剂PDTC后,胞浆IkBα的下降和胞核内NF-κB p65的增加均被抑制,同时IL-1β和TNFαmRNA的表达亦受到抑制,PDTC的抑制效果呈剂量依赖性。结论 Aβ可通过激活小胶质细胞NF-κB信号通路促进IL-1β和TNFα的表达。

Study on the inflammation induced by β-amyloid in Bv2 microglia cells

Objective Explore the molecular mechanisms of the inflammation induced by β-amyloid（Aβ） in BV2 cells,a mouse microglial cell line. Methods Cultured BV2 cells were treated with Aβ1-42 with or without Pyrrolidinedithiocarbamate ammonium（PDTC）.Then we used RT-PCR assay for interleukin-1β（IL-1β） and tumor necrosis factor α（TNFα） mRNA,western blot analyses for IκBα and NF-κB p65. Results PDTC attenuated the gene expressions of IL-1β and TNFα,inhibited the degradation of IκBα and the translocation of NF-κB p65 subunits into the nucleus of Aβ-stimulated BV2 cells,and the inhibitory effects were dose dependently elevated. Conclusion Our findings suggest that IL-1β and TNFα mRNA are induced by Aβ via the NF-κB signal pathway in BV2 microglial cells.